Air spring



Nov. 20 1923. 75,0 9

F. S, CHURCH AIR SPRING Filed May 31. 1921 2 Sheets-Sheet 1 HGJ 2a a z 6 ll 20 at 5 mnnn lNVENiOfi Patented Nov. 20, 1923.

UNITED STATESPATENT OFFICE.-

FRANK S. CHURCH, OF CINCINNATI, OHIO, ASSIGNOR 0F ONE-HALF TO THE THOS. J. CORCORAN LAMP CO., OF CINCINNATI, OHIO, A CORPORATION OF OHIO.

AIR SPRING.

Application filed May 31, 1921. Serial No. 473,873.

T 0 all whom it may concern:

Be it known that I, FRANK S. CnnRoH, a citizen of the United States, residing at Cincinnati, in the county of Hamilton and State of Ohio, have in ented a new and useful Air Spring/of which the following is a specification.

This invention relates to an improved air spring of the annular tube diaphragm type disclosed in my Patent 1,403,466, issued Jan. 10, 1922, but the present invention has certain features of novelty over the invention described in the above patent, which will be fully set forth hereinafter.

An object of the air spring improvements now to be described is to render springs of the annular tube ty e more effective in the performance of the unctions for which they are designed by giving greatly increased snubbing action without det-rimentally affecting the main or primary shock absorbing action of the spring.

These and other objects are attained in the construction described in the following specification and illustrated in the accompanying drawings in which:

Fig. 1 is a sectional elevation of an 3,11 spring disclosing a construction embodying one form of the improvements of the present invention, showing the spring in normal condition.

Fig. 2 is a, view of the spring shown in Fig. 1, but taken on the line 2-2 thereof, showing in full lines the parts moved to occupy the positions assumed during a movement impelled by a main or primary shock, and showing in dotted lines the positions assumed by the parts upon a snubbing move ment responsive to a secondary or rebound shock. v

In my improved air spring I will consider the spring as consisting of four main portions which in their cooperative relat on to one another operate to produce a spring of greatly increased eificiency over the spring set forth in my patent to which I have referred above. These four portions are an outer member 5, an inner member 6, a shock absorbing cushion 7 and a snubbing valve construction 8.

The outer member 5 is of dome-shaped contour, the upper part containing the snubhing valve 8 and the lower part having an enlarged mouth formed by making a double or reversely curved expansion 9 against which the cushion 7 bears and operates. To the lower inner edge of the member 5 a spring-attaching bracket 10 is secured, although it; may as readily be formed integrally with the member 5 as by drawing or casting.

The inner member 6 is, as in the construction in the application referred to above, of substantial hourglass shape which fits the shape of the tube or cushion 7 when in normal position as shown in Fig. 1, but which has reverse curves at its upper and lower edges, over which the tube rolls when the two members are moved relatively to one another as shown in Fig. 2. In the central web of the member 6 a bleedor passage 11 is provided for a purpose which will be described. Spring attaching lugs 12 are provided on the lower edge of the member 6 to cooperate with the bracket, 10 in attaching the spring to a vehicle, and in the particular form shown, I have provided a stop lug 13 for co operation with the vehicle perch 14 to prevent excessive rocking movement of the sprlng.

The cushion 7 is of the annular tubular type and may be made of rubber impregnated fabric or wrapped cord and rubber in much the same manner as the usual pneumatic tire, being supplied with an inflating valve 15 as is usual in tire constructions. However the cushion may be made other than pneumatic by making it solidly of a resilient material such as sponge rubber or the like.

The snubbing valve construction 8 is located in the top of the member 5 for the purpose of utilizing the space within the dome, between member 6 and the top of the dome, for a snubbing chamber in which the compression and rarification phenomena of air is utilized in the snubbing action of the spring. The type of valve I have shown consists of a valve cap 16 screwed into a boss 17 in the top of the dome, the cap being hollow and having vent passages 18 beneath its top 19. Beneath the cap 16 and passing through the boss 17, a passage 20 is formed, having a frusto-conieally enlarged upper end in which a conical valve 21 is seated; The valve is provided with a stem which fits loosely within the cap- 16 and which is hollow to contain a spring 22, which, being located between the cap and valve, retains the valve .yieldingly on its seat. The stem isof 'sufiicient length to abut ;the under face of the cap when the valve is open, and yet not stop the flow of air through the va ve by bringing it into contact with the cap projection. In the operation of my improved air spring construction the main or primary shock will cause the running gear of the vehicle, which is attached to the lugs 12, to move upwardly with relation to the body or chassis, which is attached to bracket. 10. This action causes the inner member 6- to move upwardly as shown in the full lines in Fig. 2, thus causing the inflated cushion to be rolled upon the reversely curved portions of the inner and outer members to compress it and give it a tendency to move the members back to normal position, or in other words to resist the movement of the inner member from its normal position. During such an action, the air within the dome is compressed to cause valve 21 to open against the tension of spring 22, thus allowing the air to be forced out through the cap. When normal pressure has been established within the dome, the valve will close. The rebound or secondary movement of the members will be caused by the moving apart of'the chassis and runnin gear to bring the members to the dotted line positions shown, in which the tube is again rolled and compressed, but in an opposite direction to that caused by the main or primary shock movement. The valve 21, being closed, will prevent air entering the increased space within the dome, and the remaining air therein will hence become greatly rarified, thus creating a par-- tial vacuum whereby the rebound movement is resisted. In addition to this air rarification within the dome, the rebound movement is resisted by the rolling and compression of the cushion. However, in order to restore normal pressure within the dome after the snubbing has been effected, I have provided bleeder passage 11 through which the air gradually passes until either the pressure is normal or the inner member again moves in response to a main or initial shock. Under actual working conditions it will be understood that as a matter of fact the movements of the inner and outer members will be greatly modified and that the action of valve 21 will probably be a continual series of relatively rapid vibrations, with the air passing through passage 11 in a series of short pufi's to restore that displaced through valve 21.

Various departures may be made from the exact embodiment of the invention disclosed herein, without deviating from the spirit and scope of my invention as set forth in the appended claims, but it will be readily understood that in any form of its embodiment the invention as it is set; forth herein consists in providing additional means for effectively snubbing the rebound or second ary shock occasioned bythe reaction of the main or primary shock movement of the spring.

Although I have described the snubbing valve 8 as being located in the top of the outer dome-like member, and although I have described the valve as being of the particular type shown in the drawings, it will be readily understood that the position of the valve and its construction may be materially changed without affecting the operation of the air sprin in any manner.

Having thus descri d my invention what I claim is: i

1. An air spring for vehicles comprising a substantially annular air cushion, a. member located within the cushion and having curved surfaces adapted to engage a portion of the curved walls thereof, a member surrounding the cushion and having curved surfaces adapted to engage a portion of the curved walls thereof opposite that portion engaged by the first mentioned member, and a valve located in the outer member adapted to open in response to an increase of pressure within the outer member, said inner member having a passage therein communieating with the interior of the outer member, adapted to permit the restoration of normal pressure within the outer member after air has been discharged therefrom in response to the opening of the valve.

2. In combination in an air spring, an air cushion having substantially annular formation, a shell-like outer member having a. curved wall lower portion adapted to fit substantially the outer half of the exterior surface of the cushion, with a substantially cylindrical upper portion, an inner member having a substantially hour glass shape adapted to conform substantially to the curvature of the cushion walls surrounding the opening thereof and to be moved within the cylindrical upper portion of the outer member, and a valve in the outer member adapted to open in response to increases of pressure within the outer member to permit a discharge of air therefrom when the inner member is moved into the interior of the outer member and to close when excess of pressure has been relieved, said inner member having a bleeder passage therein adapted gradually to permit of restoration of normal pressure within the outer member when the inner member is withdrawn from the outer member.

FRANK s. CHURCH. 

